<html xmlns="http://www.w3.org/1999/xhtml" xmlns:math="http://www.w3.org/1998/Math/MathML">
<head>
<script>
function boom()
{
  var span = document.getElementById("s");
  var newSpan = document.createElementNS("http://www.w3.org/1999/xhtml", "span");
  span.appendChild(newSpan);
}
</script>
</head>
<body onload="boom();">
<math:math><span id="s"><div/></span></math:math>
</body>
</html>
